In a typical system for data communication according to one or more Consultative Committee for Space Data Systems (CCSDS) protocols, a single ground station receives data from a single data source (such as a spacecraft). A single facility (and possibly a backup facility) then processes the data. Data latency of up to approximately three hours often occurs in such a system. In the National Aeronautics and Space Administration's (NASA's) Earth Observing System (EOS), spacecraft communicate data through NASA's Space Network (also known as the Tracking and Data Relay Satellite System (TDRSS)) or through polar ground stations, usually on a once-per-orbit basis. In EOS, data is typically received in order and from only a single source.